Tach not reading properly

[Lawns570]

96 75hp force. When I start it up my take is reading 8,000rpm. I can clearly hear my engine is not rev"d that high. I tested the battery to see if the volt regulator was working and it's charging at 17v while it running?? I was wondering if this is to high and could that be sending a higher voltage to the tach, hence my problem?

 

[Lawns570]

Also this reading was taking at the battery. The dash voltage reading is 13-14v

 

[GA_Boater]

Something isn't right. A 3 volt difference means a connection/corrosion problem. At the battery check the voltage on the posts and on the battery connectors - Should be exactly the same.

 

[Jiggz]

First you need to verify the voltmeter and also your multimeter. Test the multimeter at the battery terminal with the motor off or not running. Do you read 12~13 VDC? Now go to the dash voltmeter, behind there should be a red terminal or wire and a ground wire, turn the ignition switch to on but do not start the motor, check voltages on the dash voltmeter and then read it also with your multimeter, are they same or at least you can tell how much they differ from each other. If the dash reads the same then you know it is should be reading OK and same with the multimeter. Now ran the engine and check the voltages again and post back your readings. As for the tach, it gets its signal from the rectifier input terminals. So make sure the connection is not loose.